Sir Mark Thatcher

Sir Mark Thatcher has admitted his part in an alleged plot to overthrow the government of Equatorial Guinea.

The son of former Tory prime minister Baroness Thatcher pleaded guilty in a South African court on Thursday over his part in the plan.

The controversial businessman accepted that he broke anti-mercenary legislation by agreeing to charter a helicopter, but denied any knowledge of what it was for.

Sir Mark was arrested last August over his suspected role in the plot and has agreed to pay a £265,000 fine in lieu of a custodial sentence.

However he has received a four-year suspended jail sentence and is now set to leave South Africa, where he has lived since 1995, in favour of the US.

Outside the Cape Town court Sir Mark said: "There is no price too high for me to pay to be reunited with my family and I am sure all of you who are husbands and fathers would agree with that."

The news of his release will come as a relief to his mother Margaret, who, in already fragile health, is reported to have been deeply concerned over the case.

Sir Mark, who inherited his title from his late father in 2003, has hit the headlines over the years with a series of controversial episodes.

In 1982, when his mother was prime minister, he had to be rescued from the Sahara after being stranded taking part in the Paris to Dakar race.

His company Mark Thatcher Racing developed cash problems and in 1986 the prime minister faced questions over his relationship with the Sultan of Brunei.

She also faced parliamentary questions over his involvement in a contract to build a university in Oman in 1984.

He was representing a British company, which won the contract after the then Mrs Thatcher urged the Omanis to give the work to Britain during an official visit.

In 1998 a loans scheme in which Sir Mark was involved was investigated by authorities in South Africa, which he had made his home, but no wrong doing was found.